Plasma-assisted catalytic methanation of CO and CO2 over Ni–zeolite catalysts

Insight into CO2 methanation mechanism over NiUSY zeolites: An operando IR study

“…Among this wide variety of supports and metals studied, few attention has been paid for Ni/zeolite catalysts despite an interesting catalytic activity with [16] or without plasma-assistance [12]. In fact, our former results [12] showed that NiUSY zeolites could promote CO 2 hydrogenation into methane with conversions and selectivities comparable to those found for the best CO 2 methanation catalysts reported in the literature [11], that use potentially more expensive bulk cerium oxide supports.…”

“…The adsorbed CO can be further dissociated into adsorbed C and O, which are hydrogenated respectively to CH 4 and H 2 O [17]. The pathway involving direct dissociation of CO 2 , corroborated by DFT studies [16], does not totally match with the CO 2 methanation. Indeed, the presence of H 2 in the gas feed is important only after the CO dissociation, whereas other DFT [20] and experimental [10] studies have highlighted the formation of products such as formates, which are energetically more favorable than the direct dissociation.…”

“…On the one hand, adsorbed CO formed by direct dissociation or disproportionation onto nickel metallic particles [18] or by partial reduction of carbonate and/or formate intermediates [19], is considered as the "true" intermediate involved in the CH 4 formation. The CO formation by direct dissociation is thought to occur exclusively on metallic species such as Rh or Ni [16], whereas the formation of carbonates implies such adsorption/activation sites of CO 2 (i.e., basic sites) [10]. The adsorbed CO can be further dissociated into adsorbed C and O, which are hydrogenated respectively to CH 4 and H 2 O [17].…”

A study on CO2 and CH4 conversion to synthesis gas and higher hydrocarbons by the combination of catalysts and dielectric-barrier discharges

“…Jwa et al also reported that the Ni particle size was reduced from 25.8 nm to 18.7 nm after plasma assisted catalytic methanation of CO and CO 2 over Ni-zeolite catalysts at low temperatures (180-260 • C) and ambient pressure [52].…”

“…Recently, Jwa et al studied the plasma assisted catalytic methanation of CO over Nizeolite catalysts [52]. They found that the conversion of CO to CH 4 was greatly promoted by plasma.…”